A ground speed control system for an outdoor power equipment unit comprises a slidable handle grip that moves up and down on a handle to decrease and increase the ground speed, respectively. A pivotal control lever is provided on the handle grip. The pivotal lever includes a toothed sector gear. A toothed rack is fixed to the handle. Normally, the sector gear and toothed rack are out of engagement with each other during sliding motion of the handle grip. However, if the operator pivots the control lever to engage the sector gear with the rack, cooperation between the teeth of the sector gear and the teeth of the rack will move the slidable handle grip further down the handle to provide a temporary speed increase and will also lock the handle grip to the handle to provide cruise control capability. The handle grip is U-shaped and has two legs telescopically received inside the open upper ends of a pair of spaced handle tubes.